Transfer of cytoplasmic male sterility from alloplasmicBrassica junceaandB. napusto cauliflower (B. oleraceavar.botrytis) through interspecific hybridization and embryo culture

Abstract

Cytoplasmic male sterile (CMS) lines of Brassica juncea and B. napus with the mitochondrial genome of Moricandia arvensis and Erucastrum canariense, respectively, were used to transfer CMS to cauliflower (B. oleracea). Embryo culture was essential to recover these interspecific hybrids. Success of embryo rescue was dependent on the post-pollination age of the ovary; ovaries excised at 9- and 14- days-afterpollination gave the best response in B. napus x B. oleracea and B. juncea x B. oleracea, respectively. Embryo rescue was also necessary in BC1 and BC2 to obtain progenies. Recovery of the recurrent parent phenotype was faster in B. napus x B. oleracea than B. juncea x B. oleracea. BC3 generation plants of B. napus x B. oleracea showed good curd formation and complete male sterility and nine bivalents at meiosis whereas those of B. juncea x B. oleracea were male sterile but still had genetic elements of B. juncea.